1. Field of the Invention
This invention relates to a double-structure synchronizer ring and its manufacturing method. More particularly, this invention relates to a novel type of double-structure synchronizer ring and its manufacturing method using raw material powder which is press molded and sintered. The synchronizer ring according to this invention is constructed in such a manner as to separate into an inter-diameter indentation portion comprising copper powder sintering agent and an external ring body portion comprising sintering metal and then, to indent the inter-diameter indentation portion into an inter-diameter of the external ring body portion, so as to embody an integrated form of the synchronizer ring. The synchronizer ring according to this invention has a better friction force and cost-saving benefits.
2. Background of the Related Art
A synchronous ring plays a frictional role between two gears in order to impart the same relative velocity between gears having different velocities in hand transmission gears boxes of automobiles.
As illustrated in FIG. 1, the conventional synchronizer ring has a single structure and in particular, its ring body portion comprises a brass forging agent containing copper as a main ingredient, and other materials, such as, aluminum, manganese, silicon, iron, chromium, nickel, lead and zinc.
According to a process for manufacturing a conventional synchronizer ring containing a brass forging agent, a common type of the synchronizer ring contains 59-65 weight % of copper, 1.7-3.7 weight % of aluminum, 2.2-3.8 weight % of manganese, 0.5-1.3 weight % of silicon, less than 0.6 weight % of iron, 0.07-0.27 weight % of chromium, 0.2-0.6 weight % of nickel, less than 0.18 weight % of lead and the remaining amount comprising zinc. A conventional synchronizer ring is prepared in a forged molding process, such as a continuous casting method or an extrusion method. The continuous casting method involves dissolving the ingredients into a mixture, delivering the mixture in liquid metal form, and continuous casting, cutting and processing operations. On the other hand, the extrusion method involves dissolving the ingredients, billet fabrication (SEMI continuous casting), cutting, line-up, hot extrusion, lineal alignment, and other suitable processing operations.
However, since a synchronizer ring is inserted into a synchronizer hub (not illustrated) to perform sliding movement toward axial direction, conventional ring materials tend to be expensive and wear easily.